Substrate holding and rotating device, substrate treatment apparatus including the device, and substrate treatment method

ABSTRACT

A substrate holding and rotating device includes: a turntable rotatable; a rotative drive unit which rotates the turntable; a holding member which is provided on the turntable and horizontally holds a substrate in upwardly spaced relation to the turntable; a vertically movable protection disk disposed between the turntable and a substrate holding position; and a magnetic levitation mechanism including a first magnet attached to the protection disk, an annular second magnet which generates a repulsive force with respect to the first magnet, a support member which non-rotatably supports the second magnet, and a relative movement mechanism which moves the support member and the turntable relative to each other.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate holding and rotatingdevice, a substrate treatment apparatus including the device, and asubstrate treatment method. Exemplary substrates to be held or treatedinclude semiconductor wafers, substrates for liquid crystal displaydevices, substrates for plasma display devices, substrates for FED(Field Emission Display) devices, substrates for optical disks,substrates for magnetic disks, substrates for magneto-optical disks,substrates for photo masks, ceramic substrates, and substrates for solarcells.

2. Description of Related Art

U.S. Pat. No. 5,601,645 (hereinafter referred to as “U.S. Pat. No.5,601,645”) discloses a substrate rotating and holding device for asubstrate spin treating apparatus. The substrate rotating and holdingdevice includes a turntable to be rotated by rotation means, and supportmeans which horizontally positions a substrate held by the turntable soas to space the substrate a predetermined distance from a surface of theturntable. A vertically movable member having substantially the samesize as the substrate is provided on the turntable. In a substratetreatment process during which the turntable is rotated, the verticallymovable member is located at an upper position adjacent to thesubstrate. Thus, as stated in U.S. Pat. No. 5,601,645, a distancebetween a lower surface of the substrate and an upper surface of thevertically movable member is reduced, whereby mist generated during thesubstrate treatment process is prevented from flowing below the lowersurface of the substrate.

An arrangement shown in FIGS. 1 to 3 in U.S. Pat. No. 5,601,645 isadapted to vertically move up and down the vertically movable memberrelative to the turntable by means of a push-up mechanism which operatesin response to a centrifugal force generated by the rotation of theturntable. In an arrangement disclosed in FIGS. 7 and 8 of U.S. Pat. No.5,601,645, fins are provided in an outer peripheral portion of thevertically movable member and, when the vertically movable member isrotated by the rotation of the turntable, the fins depress ambient gasto generate a lift force to lift the vertically movable member.

With these arrangements, however, it is impossible to move thevertically movable member sufficiently close to the lower surface of thesubstrate, because the centrifugal force or the lift force cannot besufficiently generated when the substrate is rotated at a lower rotationspeed. As a result, the mist generated during the substrate treatmentprocess is liable to adhere to the lower surface of the substrate. Wherean upper surface of the substrate being rotated is scrubbed with abrush, for example, the rotation speed of the substrate is about 100rpm, making it impossible to sufficiently provide the centrifugal forceor the lift force. Therefore, mist of a treatment liquid is liable tointrude into a space defined between the lower surface of the substrateand the vertically movable member during the scrubbing of the uppersurface of the substrate, thereby contaminating the lower surface of thesubstrate.

An arrangement disclosed in FIGS. 9 and 10 of U.S. Pat. No. 5,601,645 isadapted to vertically move up and down the vertically movable member bya push-up mechanism utilizing an air cylinder. Further, an arrangementshown in FIGS. 11 and 12 of U.S. Pat. No. 5,601,645 includes bellowsfixed to the vertically movable member at one end thereof, and isadapted to vertically move up and down the vertically movable member bypressurizing and evacuating the inside of the bellows for expansion andcontraction of the bellows.

However, these arrangements each have a complicated structure, becausedriving means for the vertical driving is incorporated in a rotationsystem including the turntable and the vertically movable member, andrequires supply of a driving force. In addition, there is a need forsupplying and sucking driving air to/from a non-rotation system, so thata slide portion kept in frictional contact with an air supply/suctionpassage is present between the non-rotation system and the rotationsystem. This may result in generation of particles, which may adverselyinfluence the substrate treatment.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a substrate holdingand rotating device which has a simplified construction and yet iscapable of protecting a lower surface of a substrate irrespective of therotation speed of the substrate and suppressing generation of particlesattributable to the frictional contact, and to provide a substratetreatment apparatus including such a substrate holding and rotatingdevice. It is another object of the present invention to provide asubstrate treatment method which ensures reliable protection of a lowersurface of a substrate without a need for a complicated arrangement evenif the substrate is rotated at a lower rotation speed, and permits ahigh-quality substrate treatment while suppressing generation ofparticles attributable to the frictional contact.

According to the present invention, there is provided a substrateholding and rotating device, which includes: a turntable rotatable abouta vertical rotation axis; a rotative drive unit which rotates theturntable; a holding member which is provided on the turntable andhorizontally holds a substrate in upwardly spaced relation to theturntable; a protection disk having substantially the same size as thesubstrate held by the holding member; and a magnetic levitationmechanism which levitates the protection disk from the turntable. Theprotection disk is disposed between the turntable and a substrateholding position at which the substrate is held by the holding member,and attached to the turntable so as to be vertically movable relative tothe turntable between a lower position and an adjacent position close toa lower surface of the substrate held by the holding member above thelower position. The magnetic levitation mechanism includes a firstmagnet attached to the protection disk, a second magnet which has anannular shape coaxial about the rotation axis and generates a repulsiveforce with respect to the first magnet, a first support member whichnon-rotatably supports the second magnet, and a first relative movementmechanism which moves the first support member and the turntablerelative to each other so as to change a distance between the firstmagnet and the second magnet. The magnetic levitation mechanism isconfigured to levitate the protection disk from the turntable by therepulsive force generated between the first magnet and the secondmagnet.

With this arrangement, the holding member is provided on the turntablewhich is to be rotated by the rotative drive unit. The substrate ishorizontally held as upwardly spaced from the turntable by the holdingmember. The protection disk having substantially the same size as thesubstrate is attached to the turntable. The protection disk isvertically movable relative to the turntable. That is, the protectiondisk is vertically movable relative to the turntable between the lowerposition and the adjacent position close to the lower surface of thesubstrate held by the holding member above the lower position. Themagnetic levitation mechanism is provided for driving the protectiondisk. More specifically, the magnetic levitation mechanism includes thefirst magnet attached to the protection disk, the second magnetnon-rotatably supported by the first support member, and the firstrelative movement mechanism which moves the first support member and theturntable relative to each other.

With this arrangement, the first support member and the turntable aremoved relative to each other so that the second magnet is located at aposition sufficiently close to the first magnet below the first magnet,whereby the protection disk is levitated from the turntable to theadjacent position and held at the adjacent position by the repulsiveforce generated between the first magnet and the second magnet.

A driving force is transmitted from a non-rotation system to a rotationsystem in a non-contact manner by utilizing the repulsive magnetic forcegenerated between the second magnet in the non-rotation system and thefirst magnet in the rotation system. With a simplified construction,therefore, the protection disk can be held at the adjacent position bythe driving force transmitted in the non-contact manner even if theturntable is rotated and the first magnet attached to the protectiondisk is correspondingly rotated.

Even if the turntable is rotated at a lower rotation speed or is notrotated, the repulsive force generated between the first magnet and thesecond magnet levitates the protection disk from the surface of theturntable by moving the first support member and the turntablesufficiently close to each other. Therefore, the protection disk can belocated sufficiently close to the lower surface of the substrate.

Thus, the inventive substrate holding and rotating device has asimplified construction, and yet is capable of reliably protecting thelower surface of the substrate irrespective of the rotation speed of thesubstrate and suppressing generation of particles which may otherwiseoccur due to frictional contact during rotation.

With the protection disk located at the lower position, a space isdefined between the protection disk and the lower surface of thesubstrate. Therefore, a substrate transport robot utilizes this space totransfer the substrate to the holding member and to receive thesubstrate from the holding member.

The second magnet preferably has an annular magnetic pole coaxial aboutthe rotation shaft. More specifically, the second magnet preferably hasan annular magnetic pole corresponding to a rotation locus of the firstmagnet. Thus, the repulsive force continuously and stably acts betweenthe first magnet and the second magnet even when the first magnet isrotated together with the turntable. Therefore, the protection disk canbe reliably held at the adjacent position.

The first relative movement mechanism may be a mechanism whichvertically moves up and down the first support member, a mechanism whichvertically moves up and down the turntable, or a mechanism whichvertically moves up and down both the first support member and theturntable.

The first relative movement mechanism is not necessarily required to bea mechanism which vertically moves the first support member and theturntable relative to each other, but may be configured to move thesecond magnet toward the first magnet in a direction crossing therotation axis so as to cause the repulsive force to act between thefirst magnet and the second magnet.

According to an embodiment of the present invention, the holding memberincludes a movable holding member which is movable between a holdingposition at which the movable holding member holds the substrate and aretracted position to which the movable holding member is retracted fromthe holding position, and the substrate holding and rotating devicefurther includes a magnetic drive mechanism including a first magneticmember attached to the movable holding member, a second magnetic memberwhich has an annular shape coaxial about the rotation axis and generatesa magnetic force with respect to the first magnetic member, a secondsupport member which non-rotatably supports the second magnetic member,and a second relative movement mechanism which moves the second supportmember and the turntable relative to each other so as to change adistance between the first magnetic member and the second magneticmember, the magnetic drive mechanism being configured to hold themovable holding member at the holding position by the magnetic forcegenerated between the first magnetic member and the second magneticmember.

With this arrangement, the movable holding member can be held at theholding position in a non-contact manner by utilizing the magnetic forcegenerated between the first magnetic member attached to the movableholding member and the second magnetic member non-rotatably supported bythe second support member. Therefore, the movable holding member can beheld at the holding position by a simplified arrangement. In addition,transmission of a driving force for holding the movable holding memberat the holding position can be achieved in a non-contact manner byutilizing the magnetic force. This further suppresses the generation ofparticles which may otherwise occur due to the frictional contact duringthe rotation.

Since the second magnetic member is coaxial about the rotation axis, themagnetic force can stably act between the first magnetic member and thesecond magnetic member at any rotation angular position when the firstmagnetic member is rotated together with the turntable. Therefore, themovable holding member can be reliably held at the holding position,whereby the substrate can be reliably held.

At least one of the first magnetic member and the second magnetic memberis preferably a magnet.

The second relative movement mechanism may be a mechanism whichvertically moves up and down the second support member, a mechanismwhich vertically moves up and down the turntable, or a mechanism whichvertically moves up and down both the second support member and theturntable. Further, the second relative movement mechanism is notlimited to the mechanisms adapted to vertically move up and down thesecond support member and/or the turntable, but may be a mechanismconfigured, for example, to move the second support member in adirection crossing the rotation axis to move the second magnetic membertoward or away from the first magnetic member.

According to another embodiment of the present invention, the secondmagnetic member, the second support member and the second relativemovement mechanism serve as the second magnet, the first support memberand the first relative movement mechanism, respectively, and themagnetic drive mechanism and the magnetic levitation mechanism share thesecond magnet, the first support member and the first relative movementmechanism. When the second magnet is located at a predeterminedposition, the protection disk is held at the adjacent position by therepulsive force generated between the second magnet and the firstmagnet, and the movable holding member is held at the holding positionby the magnetic force generated between the second magnet and the firstmagnetic member.

With this arrangement, the magnetic drive mechanism and the magneticlevitation mechanism share the second magnet, the first support memberand the first relative movement mechanism, and the turntable and thefirst support member are moved relative to each other by the firstrelative movement mechanism to drive the protection disk as well as themovable holding member. This further simplifies the construction of thedevice.

According to further another embodiment of the present invention, thesubstrate holding and rotating device further includes a limitationmember which limits upward relative movement of the protection disk withrespect to the turntable at the adjacent position. With thisarrangement, the upward relative movement of the protection disklevitated by the magnetic force is limited by the limitation member, sothat the protection disk can be reliably located at the adjacentposition close to the lower surface of the substrate. Particularly,where the adjacent position is such that the protection disk does notcontact the lower surface of the substrate but is spaced a minutedistance from the lower surface of the substrate, the minute distancecan be maintained between the protection disk and the lower surface ofthe substrate.

According to still another embodiment of the present invention, thesubstrate holding and rotating device further includes a guide mechanismwhich is provided on the turntable and guides the vertical relativemovement of the protection disk. This arrangement stabilizes thevertical movement of the protection disk relative to the turntable.

According to further another embodiment of the present invention, thesubstrate holding and rotating device further includes a lateral sidecovering member which is attached to the turntable and covers the spacedefined between the substrate held by the holding member and theturntable from a lateral side. With this arrangement, the space definedbetween the turntable and the substrate is covered from the lateralside, so that an ambient atmosphere is substantially prevented frombeing caught into the space from the lateral side. This stabilizes a gasstream flowing around the substrate during the rotation of thesubstrate.

The lateral side covering member is preferably fixed to the protectiondisk. In this case, the space defined between the protection disk andthe turntable is preferably covered by the lateral side covering memberwith the protection disk being located at the adjacent position. Whenthe protection disk is located at the lower position, the lateral sideof the space defined between the protection disk and the lower surfaceof the substrate is preferably open, so that the space can be utilizedfor loading and unloading the substrate.

According to the present invention, there is provided a substratetreatment apparatus which includes the substrate holding and rotatingdevice having the aforementioned features, and a treatment liquid supplyunit which supplies a treatment liquid to an upper surface of asubstrate held by the substrate holding and rotating device.

With this arrangement, the upper surface of the substrate is treatedwith the treatment liquid by supplying the treatment liquid to the uppersurface of the substrate while covering a lower surface of the substratewith the protection disk. Therefore, even if mist of the treatmentliquid is generated, the mist is substantially prevented from reachingthe lower surface of the substrate. As a result, the upper surface ofthe substrate can be selectively treated, while the lower surface of thesubstrate is kept clean without supplying the treatment liquid to thelower surface of the substrate. More specifically, the upper surface ofthe substrate can be treated with the treatment liquid with the lowersurface of the substrate kept dry without contamination of the lowersurface of the substrate.

As described above, the substrate holding and rotating device has asimplified construction and yet is capable of reliably protecting thelower surface of the substrate with the protection disk held at theadjacent position even when the substrate is rotated at a lower speed ornot rotated. Further, the generation of particles can be suppressedwhich may otherwise occur due to the sliding during the rotation. Thismakes it possible to selectively treat the upper surface of thesubstrate with the treatment liquid in a clean environment, whilesuppressing the generation of particles and the adhesion of the mist tothe lower surface of the substrate without the need for a complicatedarrangement.

According to an embodiment of the present invention, the substratetreatment apparatus further includes a receiving member which receives atreatment liquid supplied from the treatment liquid supply unit to thesubstrate held by the substrate holding and rotating device and flowingoutward from the surface of the substrate. Further, the first supportmember is fixed to the receiving member, and the first relative movementmechanism is configured to move the receiving member and the turntablerelative to each other. With this arrangement, a mechanism for therelative movement of the turntable and the receiving member whichreceives the treatment liquid flowing outward from the surface of thesubstrate doubles as a mechanism for moving the first support memberwhich supports the second magnet. This further simplifies theconstruction of the substrate treatment apparatus.

More specifically, where a positional relationship between the receivingmember and the turntable is such that the receiving member receives thetreatment liquid flowing outward from the surface of the substrate at atreatment position, the protection disk is preferably held at theadjacent position by the repulsive force generated between the first andsecond magnets. Further, the movable holding member is preferably heldat the holding position while the magnetic force of the second magnet isreceived by the first magnetic member with the receiving member locatedat the treatment position.

According to another embodiment of the present invention, the substratetreatment apparatus further includes an inert gas supply unit whichsupplies an inert gas to a space defined between the substrate held androtated by the substrate holding and rotating device and the protectiondisk located at the adjacent position. With this arrangement, the inertgas is supplied to the space defined between the protection disk and thesubstrate, thereby more effectively suppressing the adhesion of thetreatment liquid mist to the lower surface of the substrate.

According to further another embodiment of the present invention, theprotection disk has a restriction portion provided on an upper surfacethereof for restricting an inert gas flow passage on a peripheral edgeof the substrate held by the holding member. With this arrangement, theinert gas flow passage is restricted on the peripheral edge of thesubstrate, so that an inert gas flow speed is increased around thesubstrate. This more effectively suppresses the intrusion of thetreatment liquid mist into the space defined between the protection diskand the lower surface of the substrate.

According to still another embodiment of the present invention, theinert gas supply unit includes an inert gas nozzle which ejects theinert gas radially toward the peripheral edge of the substrate held bythe holding member from the rotation center of the turntable. With thisarrangement, an inert gas stream flowing toward the peripheral edge ofthe substrate from the rotation center of the turntable can be stablyformed in the space defined between the protection disk and the lowersurface of the substrate by ejecting the inert gas radially from theinert gas nozzle. This more effectively suppresses the intrusion of thetreatment liquid mist into the space.

According to the present invention, there is provided a substratetreatment method to be performed by utilizing a substrate holding androtating device, the substrate holding and rotating device including aturntable rotatable about a vertical rotation axis, a holding memberwhich horizontally holds a substrate, a protection disk attached to theturntable in relatively vertically movable manner and havingsubstantially the same size as the substrate, a first magnet attached tothe protection disk, and an annular second magnet non-rotatably providedcoaxially about the rotation axis, the substrate treatment methodincluding: a holding step of causing the holding member to horizontallyhold the substrate; a rotating step of rotating the substrate held bythe holding member by rotating the turntable; a lower surface coveringstep of moving the first magnet and the second magnet toward each otherto levitate the protection disk from the turntable to an adjacentposition close to a lower surface of the substrate by a repulsive forcegenerated between the first magnet and the second magnet to cover thelower surface of the substrate; and a treatment liquid supplying step ofsupplying a treatment liquid to an upper surface of the substrate withthe lower surface of the substrate covered with the protection disk inthe holding step and the rotating step.

According to this method, the upper surface of the substrate can betreated with the treatment liquid by supplying the treatment liquid tothe upper surface of the substrate while rotating the substrate andcovering the lower surface of the substrate with the protection diskattached to the turntable. The protection disk is kept levitated at theadjacent position close to the lower surface of the substrate by therepulsive force generated between the first magnet attached to theprotection disk and the annular second magnet provided non-rotatably.Therefore, even when the substrate is rotated at a lower speed or notrotated, the adhesion of the treatment liquid mist to the lower surfaceof the substrate can be reliably suppressed with the protection diskreliably disposed close to the lower surface of the substrate. Inaddition, the protection disk is levitated and kept in the levitatedstate by utilizing the repulsive force generated between the firstmagnet and the second magnet, thereby eliminating the need for providinga driving unit in a rotation system for vertically moving the protectiondisk. Thus, the protection disk can be moved close to the lower surfaceof the substrate, as required, without complicating the construction ofthe device. Since the first magnet and the second magnet can transmitthe repulsive force to each other in a non-contact state, the generationof particles can be suppressed which may otherwise occur due to thefrictional contact during the rotation.

According to an embodiment of the present invention, the holding memberincludes a movable holding member which is movable between a holdingposition at which the movable holding member holds the substrate and aretracted position to which the movable holding member is retracted fromthe holding position, and the holding step includes the step of holdingthe movable holding member at the holding position by applying amagnetic force to a magnetic member attached to the movable holdingmember. In this method, the movable holding member provided on theturntable is held at the holding position by utilizing the magneticforce, so that a holding force can be transmitted to the movable holdingmember in a non-contact state. This makes it possible to selectivelytreat the upper surface of the substrate with a further simplifiedconstruction while further suppressing the generation of particles whichmay otherwise occur due to the frictional contact during the rotation.

According to another embodiment of the present invention, the lowersurface covering step is the step of locating the second magnet at apredetermined position to levitate the protection disk at the adjacentposition by the repulsive force generated between the second magnet andthe first magnet, and the holding step is the step of locating thesecond magnet at the predetermined position to hold the movable holdingmember at the holding position by a magnetic force generated between thesecond magnet and the magnetic member.

In this method, it is possible to hold the protection disk at theadjacent position by the repulsive force generated between the firstmagnet and the second magnet and to hold the movable holding member atthe holding position by the magnetic force generated between the secondmagnet and the magnetic member. That is, this arrangement can be sharedfor the vertical movement of the protection disk and for the driving ofthe movable holding member. Thus, the arrangement is further simplified,making it possible to selectively treat the upper surface of thesubstrate while preventing the adhesion of the treatment liquid mist tothe lower surface of the substrate.

According to further another embodiment of the present invention, themethod further includes the step of causing a limiting member to limitupward relative movement of the protection disk with respect to theturntable at the adjacent position. This makes it possible to reliablylocate the protection disk at the adjacent position, so that thepositional relationship between the protection disk and the lowersurface of the substrate (particularly a distance between the protectiondisk and the lower surface of the substrate) can be accurately set.

According to still another embodiment of the present invention, themethod further includes the step of causing a receiving member toreceive a treatment liquid flowing outward from the substrate during therotation of the substrate. Further, the second magnet is supported bythe receiving member, and the lower surface covering step includes thestep of moving the receiving member and the turntable toward each other.In this method, when the turntable and the receiving member whichreceives the treatment liquid flowing outward from the substrate aremoved toward each other, the protection disk is levitated and held atthe adjacent position by the repulsive force generated between the firstand second magnets. That is, the arrangement for the relative movementof the receiving member and the turntable doubles as the arrangement forthe driving of the protection disk. As a result, the arrangement can befurther simplified.

When the receiving member and the turntable are moved toward each other,the magnetic force from the second magnet preferably acts on the firstmagnetic member to move the movable holding member to the holdingposition and hold the movable holding member at the holding position.Thus, the arrangement for the relative movement of the receiving memberand the turntable doubles as the arrangement for the driving of themovable holding member, so that the arrangement can be furthersimplified.

According to further another embodiment of the present invention, themethod further includes an inert gas supplying step of supplying aninert gas to a space defined between the substrate being rotated and theprotection disk located at the adjacent position in the treatment liquidsupplying step. In this method, the inert gas can be supplied to thespace defined between the protection disk and the lower surface of thesubstrate. This further suppresses the adhesion of the treatment liquidmist to the lower surface of the substrate.

According to still another embodiment of the present invention, theprotection disk has a restriction portion provided on an upper surfaceportion thereof to be opposed to a peripheral edge of the substrate heldby the holding member, and the method further includes the step ofrestricting an inert gas flow passage by the restriction portion in theinert gas supplying step. In this method, the inert gas flow passage isrestricted on the peripheral edge of the substrate, so that an inert gasstream is ejected at a higher speed outward from a gap defined betweenthe protection disk and the peripheral edge of the substrate. This morereliably suppresses the intrusion of the treatment liquid mist into thespace defined between the protection disk and the lower surface of thesubstrate.

According to further another embodiment of the present invention, theinert gas supplying step includes the step of ejecting the inert gasradially toward the peripheral edge of the substrate held by the holdingmember from the rotation center of the turntable. In this method, theinert gas stream flowing toward the peripheral edge of the substratefrom the rotation center of the turntable can be stably formed. Thismore reliably suppresses the intrusion of the treatment liquid mist intothe space defined between the protection disk and the lower surface ofthe substrate.

According to still another embodiment of the present invention, themethod further includes the step of covering the space defined betweenthe substrate held by the holding member and the turntable from alateral side by a lateral side covering member attached to the turntablein the lower surface covering step. In this method, an ambientatmosphere is less liable to be caught into the space defined betweenthe turntable and the lower surface of the substrate, so that a gasstream flowing around the turntable can be stabilized. This suppressesthe generation of the treatment liquid mist, making it possible toperform a higher-quality substrate treatment.

The foregoing and other objects, features and effects of the presentinvention will become more apparent from the following detaileddescription of the preferred embodiments with reference to the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus according to a first embodiment of thepresent invention.

FIG. 2 is a plan view for explaining a specific structure of a spinchuck provided in the substrate treatment apparatus.

FIG. 3 is a bottom view of the structure of FIG. 2.

FIG. 4 is a sectional view taken along a sectional plane IV-IV in FIG.2.

FIG. 4A is an enlarged sectional view showing a part of the structure ofFIG. 4 on an enlarged scale.

FIG. 5 is a sectional view showing an arrangement around a movable pinof the spin chuck.

FIG. 6 is a flow chart for explaining an exemplary operation to beperformed by the substrate treatment apparatus.

FIG. 7 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus according to a second embodiment of thepresent invention.

FIG. 8 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus according to a third embodiment of thepresent invention.

FIG. 9 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus according to a fourth embodiment of thepresent invention.

FIG. 10 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus according to a fifth embodiment of thepresent invention.

FIG. 11 is a diagram showing an exemplary arrangement for detecting theposition of a protection disk.

FIG. 12 is a diagram showing another exemplary arrangement for detectingthe position of the protection disk.

FIG. 13 is a diagram showing further another exemplary arrangement fordetecting the position of the protection disk.

FIG. 14 is a diagram showing still another exemplary arrangement fordetecting the position of the protection disk.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus according to a first embodiment of thepresent invention. The substrate treatment apparatus 1 is an apparatusof a single substrate treatment type adapted to treat a single substrateW (e.g., a semiconductor wafer or the like) at a time. The substratetreatment apparatus 1 includes a spin chuck 2, a rotative drivemechanism 3, a splash guard 4 and a guard drive mechanism 5.

The spin chuck 2 includes a turntable 7 rotatable about a verticalrotation axis 6. A rotation shaft 8 is connected to a lower surface ofthe turntable 7 at a rotation center via a boss 9. The rotation shaft 8extends vertically, and is configured to receive a driving force fromthe rotative drive mechanism 3 to be rotated about the rotation axis 6.The rotative drive mechanism 3 may be, for example, an electric motoremploying the rotation shaft 8 as a driving shaft. The spin chuck 2further includes a plurality of holding pins 10 (six holding pins 10 inthis embodiment) provided on an upper surface peripheral portion of theturntable 7 along a peripheral edge of the turntable 7 in spacedrelation. The holding pins 10 are arranged to horizontally hold thesubstrate W at a substrate holding height position which is spaced apredetermined distance upward from the turntable 7 having a generallyhorizontal upper surface.

The spin chuck 2 further includes a protection disk 15 disposed betweenthe upper surface of the turntable 7 and the substrate holding heightposition of the holding pins 10. The protection disk 15 is connected tothe turntable 7 in a vertically movable manner, and is movable between alower position close to the upper surface of the turntable 7 and anadjacent position spaced a minute distance from a lower surface of thesubstrate W held by the holding pins 10 in close relation to the lowersurface of the substrate W above the lower position. The protection disk15 has a disk shape having substantially the same size as the substrateW, and has notches provided at positions corresponding to the positionsof the holding pins 10 to avoid the holding pins 10.

The splash guard 4 is a tubular member laterally surrounding the spinchuck 2, and serves as a receiving member which receives a treatmentliquid flowing outward from the substrate W held by the spin chuck 2.More specifically, the splash guard 4 includes a cylindrical portion 21coaxial about the rotation axis 6, an upper guide portion 22 and a lowerguide portion 23 each projecting obliquely upward inward toward therotation axis 6 from an interior wall of the cylindrical portion 21. Theupper guide portion 22 has a partial conical surface, and its innerperipheral edge is spaced a predetermined distance outward from the spinchuck 2. The lower guide portion 23 is spaced a predetermined distancedownward from the upper guide portion 22, and also has a partial conicalsurface. The lower guide portion 23 has an inner peripheral edge locatedinward of an outer peripheral edge of the spin chuck 2 as seen in plan.A treatment liquid port 24 is defined between the upper guide portion 22and the lower guide portion 23 for receiving the treatment liquidflowing from the substrate W held by the spin chuck 2.

The guard drive mechanism 5 is provided for vertically moving up anddown the splash guard 4 along the rotation axis 6. The guard drivemechanism 5 may include a linear drive mechanism such as an air cylinderor a ball screw mechanism.

The substrate treatment apparatus 1 further includes a treatment liquidsupply unit 30 and a brush cleaning mechanism 35. The treatment liquidsupply unit 30 includes a treatment liquid nozzle 31 which spouts atreatment liquid toward a front surface of the substrate W, and isconfigured to supply the treatment liquid from a treatment liquid supplysource 32 to the treatment liquid nozzle 31 through a treatment liquidsupply tube 33. A treatment liquid valve 34 is provided in the treatmentliquid supply tube 33. Therefore, the spouting of the treatment liquidfrom the treatment liquid nozzle 31 is started and stopped by openingand closing the treatment liquid valve 34.

The brush cleaning mechanism 35 includes a cleaning brush 36 forscrubbing the substrate W in contact with an upper surface of thesubstrate W, a pivot arm 37 which holds the cleaning brush 36 at itsdistal end, and an arm drive mechanism 38 for driving the pivot arm 37.The arm drive mechanism 38 is arranged to pivot the pivot arm 37 in ahorizontal plane and vertically move up and down the pivot arm 37. Withthis arrangement, the entire upper surface of the substrate W can bescrubbed by pressing the cleaning brush 36 to the upper surface of thesubstrate W and moving a brush pressing position radially of thesubstrate W while holding and rotating the substrate W by means of thespin chuck 2.

In this scrubbing process, the treatment liquid (e.g., deionized water)is supplied from the treatment liquid nozzle 31, whereby foreign mattercan be easily removed from the front surface of the substrate W andforeign matter scrubbed away by the cleaning brush 36 can be expelledoutside the substrate W.

The rotation shaft 8 is a hollow shaft, and an inert gas supply tube 70is inserted in the inside of the hollow shaft. An inert gas supply line72 for supplying an inert gas from an inert gas supply source 71 isconnected to a lower end of the inert gas supply tube 70. An inert gasvalve 73 is provided in the inert gas supply line 72. The inert gasvalve 73 opens and closes the inert gas supply line 72. With the inertgas valve 73 open, the inert gas is supplied into the inert gas supplytube 70. The inert gas is supplied into a space defined between theprotection disk 15 and the lower surface of the substrate W by anarrangement to be described later. Thus, the inert gas supply tube 70,the inert gas supply source 71, the inert gas supply line 72 and theinert gas valve 73 collectively define an inert gas supply unit 74.

The substrate treatment apparatus 1 includes a controller 40 forcontrolling the components of the apparatus. The controller 40 isconfigured to control the rotative drive mechanism 3, the guard drivemechanism 5, the treatment liquid valve 34, the arm drive mechanism 38,the inert gas valve 73 and the like.

FIG. 2 is a plan view for explaining a specific structure of the spinchuck 2. FIG. 3 is a bottom view of the structure of FIG. 2, and FIG. 4is a sectional view taken along a sectional plane IV-IV in FIG. 2.

The turntable 7 has a disk shape extending in a horizontal plane, and isconnected to the boss 9 connected to the rotation shaft 8. The holdingpins 10 are equidistantly arranged on the peripheral portion of theupper surface of the turntable 7 along the peripheral edge of theturntable 7. The holding pins 10 include stationary pins 11 which areimmovable with respect to the turntable 7, and movable pins 12 which aremovable with respect to the turntable 7. In this embodiment, twoadjacent pins 10 serve as the movable pins 12. The holding pins 10 eachinclude a lower shaft portion 51 connected to the turntable 7, and anupper shaft portion 52 provided on an upper end of the lower shaftportion 51 unitarily with the lower shaft portion 51. The lower shaftportion 51 and the upper shaft portion 52 each have a cylindrical shape.The upper shaft portion 52 is disposed eccentrically to a center axis ofthe lower shaft portion 51. The upper end of the lower shaft portion 51and a lower end of the upper shaft portion 52 are connected to eachother by a taper surface 53 which extends downward from a peripheralsurface of the upper shaft portion 52 to a peripheral surface of thelower shaft portion 51.

As schematically illustrated in FIG. 5, the movable pins 12 are eachconnected to the turntable 7 so that the lower shaft portion 51 thereofis rotatable about a rotation axis 12 a aligning with its center axis.More specifically, a support shaft 55 is provided at a lower end of thelower shaft portion 51 and supported via a bearing 54 by the turntable7. A magnet retaining member 57 which retains a pin driving permanentmagnet 56 is connected to a lower end of the support shaft 55. The pindriving permanent magnet 56 is disposed, for example, with its magneticpole direction extending perpendicularly to the rotation axis 12 a ofthe movable pin 12.

The protection disk 15 has a generally disk shape having substantiallythe same size as the substrate W. The protection disk 15 has notches 16provided in a peripheral portion thereof at positions corresponding tothe positions of the holding pins 10 as spaced a predetermined distancefrom the peripheral surfaces of the holding pins 10 to border theholding pins 10. The protection disk 15 further has a round openingconformal to the boss 9 in a center portion thereof.

Guide shafts 17 vertically extending parallel to the rotation axis 6 areconnected to a lower surface of the protection disk 15 at positions moreremote from the rotation axis 6 than the boss 9. In this embodiment,three guide shafts 17 are disposed equidistantly circumferentially ofthe protection disk 15. More specifically, the three guide shafts 17 arearranged at angular positions corresponding to every other holding pin10 as seen along the rotation axis 6. The guide shafts 17 arerespectively connected to linear bearings 18 provided at correspondingportions of the turntable 7. The guide shafts 17 are movable vertically,i.e., parallel to the rotation axis 6, while being guided by the linearbearings 18. Therefore, the guide shafts 17 and the linear bearings 18collectively define a guide mechanism 19 which vertically guides theprotection disk 15 parallel to the rotation axis 6.

The guide shafts 17 each extend through the linear bearing 18, and eachhave a flange 20 provided at a lower end thereof as projecting outward.With the flanges 20 in abutment against lower ends of the linearbearings 18, the upward movement of the guide shafts 17 and the upwardmovement of the protection disk 15 are limited. That is, the flanges 20collectively define a limitation member which limits the upward movementof the protection disk.

Magnet retaining members 61 which each retain a protection diskpermanent magnet 60 are fixed to the lower surface of the protectiondisk 15 at positions outwardly more remote from the rotation axis 6 thanthe guide shafts 17 and inwardly closer to the rotation axis 6 than theholding pins 10. In this embodiment, the protection disk permanentmagnet 60 is retained in the magnet retaining member 61 with itsmagnetic pole direction extending vertically. For example, theprotection disk permanent magnet 60 may be fixed to the magnet retainingmember 61 so as to have an S-pole at its lower end and an N-pole at itsupper end. In this embodiment, six magnet retaining members 61 arearranged in circumferentially equidistantly spaced relation. Morespecifically, the magnet retaining members 61 are respectively disposedat angular positions between adjacent holding pins 10 (intermediatebetween adjacent holding pins 10 in this embodiment) as seen along therotation axis 6. The protection disk 15 is divided (equally divided inthis embodiment) into six angular regions defined by the six magnetretaining members 61 about the rotation axis 6, and the three guideshafts 17 are disposed in every other angular region (at the center ofevery other angular region in this embodiment).

The turntable 7 has six through-holes 62 formed at positionscorresponding to the six magnet retaining members 61. The through-holes62 are configured so that the corresponding magnet retaining members 61are inserted through the through-holes 62 vertically parallel to therotation axis 6. With the protection disk 15 located at the lowerposition, as shown in FIG. 1, the magnet retaining members 61respectively inserted through the through-holes 62 to project downwardfrom the lower surface of the turntable 7, so that the protection diskpermanent magnets 60 are located below the lower surface of theturntable 7.

The lower guide portion 23 of the splash guard 4 includes a magnetretaining portion 26 which retains a guard permanent magnet 25 providedin an upper edge portion (inner edge portion) thereof. The guardpermanent magnet 25 has an annular shape coaxial about the rotation axis6, and is disposed in a plane (horizontal plane) perpendicular to therotation axis 6. More specifically, the guard permanent magnet 25 isdisposed more remote from the rotation axis 6 than the protection diskpermanent magnets 60 and closer to the rotation axis 6 than the pindriving permanent magnets 56. That is, the annular guard permanentmagnet 25 is positioned between the protection disk permanent magnets 60and the pin driving permanent magnets 56 as seen in plan. The guardpermanent magnet 25 is disposed at a lower position than the protectiondisk permanent magnets 60. In this embodiment, the guard permanentmagnet 25 has a magnetic pole direction extending horizontally, i.e.,extending radially about the rotation axis of the turntable 7. Where theprotection disk permanent magnets 60 each have an S-pole in a lowersurface thereof, the guard permanent magnet 25 is configured so as tohave a magnetic pole having the same polarity (i.e., to have aring-shaped S-pole) on a radially inward edge thereof about the rotationaxis.

When the splash guard 4 is located at a treatment position (see FIG. 4)at which the treatment liquid flowing outward from the substrate W isreceived, the treatment liquid port 24 defined between the upper guideportion 22 and the lower guide portion 23 is horizontally opposed to thesubstrate W. With the splash guard 4 located at the treatment position,a radially outward ring-shaped magnetic pole of the guard permanentmagnet 25 is horizontally opposed to the pin driving permanent magnets56. Thus, a magnetic force is generated between the guard permanentmagnet 25 and the pin driving permanent magnets 56, whereby the movablepins 12 are moved to a holding position and held at the holdingposition.

As described above, the upper shaft portions 52 of the movable pins 12are each eccentric to the rotation axis 12 a (see FIG. 5). Therefore,the upper shaft portions 52 are each shifted between an open positionmore remote from the rotation axis 6 and a holding position closer tothe rotation axis 6 by the rotation of the lower shaft portions 51. Whenthe pin driving permanent magnets 56 receive an attractive magneticforce from the guard permanent magnet 25, the pin driving permanentmagnets 56 are each moved to the holding position at which the uppershaft portions 52 are located closer to the rotation axis 6. Since theguard permanent magnet 25 has an annular shape coaxial about therotation axis 6, the attractive magnetic force is generated between theguard permanent magnet 25 and the pin driving permanent magnets 56irrespective of the rotational angular positions of the movable pins 12about the rotation axis 6 during the rotation of the turntable 7. Thus,the movable pins 12 are each held at the holding position at which thesubstrate W is held.

On the other hand, a repulsive magnetic force acts between the guardpermanent magnet 25 and the protection disk permanent magnets 60 whenthe splash guard 4 is located at the treatment position (see FIG. 4).Therefore, the protection disk permanent magnets 60 receive an upwardexternal force. Thus, the protection disk 15 receives an upward forcefrom the magnet retaining members 61 respectively retaining theprotection disk permanent magnets 60 to be thereby held at the treatmentposition or adjacent position close to the lower surface of thesubstrate W.

When the splash guard 4 is moved down to be retracted to a retractedposition from a lateral side of the spin chuck 2, a smaller repulsivemagnetic force acts between the guard permanent magnet 25 and theprotection disk permanent magnets 60. Therefore, the protection disk 15is held at the lower position close to the upper surface of theturntable 7 by its gravity. Further, the guard permanent magnet 25 isnot opposed to the pin driving permanent magnets 56, so that no externalforce acts on the movable pins 12 for biasing the movable pins 12 to theholding position.

In this embodiment, the splash guard 4 includes a magnet retainingportion 28 provided above the upper guide portion 22 and retaining acancelation permanent magnet 27. When the splash guard 4 is located atthe lower position or retracted position, the cancelation permanentmagnet 27 is opposed to the pin driving permanent magnets 56. Thecancelation permanent magnet 27 has an annular shape coaxial about therotation axis 6, and has a ring-shaped magnetic pole provided on aradially inward edge thereof about the rotation axis of the turntable 7.The radially inward magnetic pole of the cancelation permanent magnet 27has the same polarity as the radially outward magnetic pole of the guardpermanent magnet 25. The cancelation permanent magnet 27 generates amagnetic force which acts on the pin driving permanent magnets 56 torotate the movable pins 12 to the open position. Where the guardpermanent magnet 25 has a ring-shaped N-pole on the outer edge thereof,more specifically, the cancelation permanent magnet 27 is configured tohave a ring-shaped N-pole on the inner edge thereof.

When the splash guard 4 is located at the lower position or retractedposition, the protection disk 15 is located at the lower position closeto the upper surface of the turntable 7, and the movable pins 12 areheld at the open position. In this state, a substrate transport robotwhich loads and unloads a substrate W to/from the spin chuck 2 can moveits substrate holding hand 45 into a space defined between theprotection disk 15 and the lower surface of the substrate W.

The protection disk permanent magnets 60, the guard permanent magnet 25and the guard drive mechanism 5 which moves up and down the splash guard4 collectively define a magnetic levitation mechanism 41 which levitatesthe protection disk 15 upward from the upper surface of the turntable 7by the repulsive force generated between the permanent magnet 25 and thepermanent magnets 60. Further, the pin driving permanent magnets 56, theguard permanent magnet 25 and the guard drive mechanism 5 collectivelydefine a magnetic drive mechanism 42 which holds the movable pins 12 atthe holding position by the magnetic force generated between thepermanent magnet 25 and the permanent magnets 56.

That is, the magnetic levitation mechanism 41 and the magnetic drivemechanism 42 share the guard permanent magnet 25, the splash guard 4serving as a support member which supports the guard permanent magnet25, and the guard drive mechanism 5 which moves up and down the splashguard 4. When the splash guard 4 is located at the treatment position,the protection disk 15 is held at the adjacent position by the magneticrepulsive force generated between the guard permanent magnet 25 and theprotection disk permanent magnets 60, and the movable pins 12 are heldat the holding position by the magnetic attractive force generatedbetween the guard permanent magnet 25 and the pin driving permanentmagnets 56.

As illustrated on a larger scale in FIG. 4A, the boss 9 connected to theupper end of the rotation shaft 8 supports a bearing mechanism 75 forsupporting an upper end portion of the inert gas supply tube 70. Thebearing mechanism 75 includes a spacer 77 fitted and fixed in a recess76 formed in the boss 9, bearings 78 provided between the spacer 77 andthe inert gas supply tube 70, and a magnetic fluid bearing 79 providedbetween the spacer 77 and the inert gas supply tube 70 above thebearings 78.

The boss 9 unitarily includes a flange 81 projecting outward in ahorizontal plane, and the turntable 7 is connected to the flange 81. Thespacer 77 is fixed to the flange 81 so as to hold an inner peripheraledge portion of the turntable 7 between the spacer 77 and the flange 81,and a cover 84 is connected to the spacer 77. The cover 84 has agenerally disk shape. The cover 84 has a center opening through whichthe upper end of the inert gas supply tube 70 is exposed, and a recess85 provided in an upper surface thereof with the center opening formedin a bottom of the recess 85. The recess 85 has a horizontal bottomsurface, and an inclined surface 83 having an inverted partial conicalshape and extending from a peripheral edge of the bottom surfaceobliquely outward upward. A rectification member 86 is connected to thebottom surface of the recess 85. The rectification member 86 has aplurality of legs 87 (e.g., four legs 87) circumferentially discretelyprovided in spaced relation about the rotation axis 6, and a bottomsurface 88 spaced from the bottom surface of the recess 85 by the legs87. The rectification member 86 has an inclined surface 89 having aninverted partial conical shape and extending from a peripheral edge ofthe bottom surface 88 obliquely outward upward.

The cover 84 has a flange 84 a projecting outward from an outerperipheral edge of the upper surface thereof. The flange 84 a isconfigured to be fitted with a step 15 a formed on an inner peripheraledge of the protection disk 15. That is, when the protection disk 15 islocated at the adjacent position close to the lower surface of thesubstrate W, the flange 84 a is fitted with the step 15 a, so that theupper surface of the cover 84 and the upper surface of the protectiondisk 15 are flush with each other to form a flat inert gas flow passage.

With this arrangement, the inert gas flowing out from the upper end ofthe inert gas supply tube 70 flows into a space defined by the bottomsurface 88 of the rectification member 86 in the recess 85 of the cover84. The inert gas is ejected radially away from the rotation axis 6through a radial flow passage 82 defined between the inclined surface 83of the recess 85 and the inclined surface 89 of the rectification member86. The inert gas forms an inert gas stream in the space defined betweenthe protection disk 15 and the lower surface of the substrate W held bythe holding pins 10, and is ejected from the space radially outward ofthe substrate W about the rotation axis.

The protection disk 15 has a restriction portion 90 provided on theupper surface thereof for restricting the inert gas flow passage on aperipheral edge of the substrate W held by the holding pins 10. In thisembodiment, the restriction portion 90 is a linear projection projectingupward from the peripheral edge of the protection disk 15. With thisarrangement, the inert gas stream ejected outward from the space definedbetween the protection disk 15 and the lower surface of the substrate Whas a higher flow speed, thereby reliably preventing or substantiallypreventing an ambient atmosphere (particularly the treatment liquidmist) from intruding into the space below the lower surface of thesubstrate W.

FIG. 6 is a flow chart for explaining an exemplary operation to beperformed by the substrate treatment apparatus 1. A substrate W to betreated is loaded into the substrate treatment apparatus 1 by thesubstrate holding hand 45 of the substrate transport robot, andtransferred to the spin chuck 2 (Step S1). At this time, the splashguard 4 is located at the retracted position or lower position below thelateral side of the spin chuck 2. Therefore, the cancelation permanentmagnet 27 is opposed to the pin driving permanent magnets 56, so thatthe movable pins 12 are held at the open position. Since the guardpermanent magnet 25 retained in the lower guide portion 23 of the splashguard 4 is located downwardly away from the turntable 7, a smallerrepulsive magnetic force acts between the guard permanent magnet 25 andthe protection disk permanent magnets 60. Therefore, the protection disk15 is located at the lower position close to the upper surface of theturntable 7. Therefore, the space defined between the substrate holdingheight position of the holding pins 10 and the upper surface of theprotection disk 15 is sufficient to receive the substrate holding hand45.

The substrate holding hand 45 holds the substrate W at a position higherthan the upper ends of the holding pins 10 and, in this state,transports the substrate W to above the spin chuck 2. Thereafter, thesubstrate holding hand 45 is moved down toward the upper surface of theturntable 7. During this downward movement, the substrate W istransferred from the substrate holding hand 45 to the holding pins 10.The substrate holding hand 45 is further moved down to the space definedbetween the lower surface of the substrate W and the protection disk 15,and then retracted laterally of the spin chuck 2 through a space definedbetween the two adjacent holding pins 10.

In turn, the controller 40 controls the guard drive mechanism 5 to moveup the splash guard 4 to the treatment position (Step S2). Thus, thetreatment liquid port 24 defined between the upper guide portion 22 andthe lower guide portion 23 is opposed to the spin chuck 2, morespecifically to the substrate W, from the lateral side. Further, theannular guard permanent magnet 25 retained in the inner peripheral edgeportion of the lower guide portion 23 is opposed to the pin drivingpermanent magnets 56. Thus, the movable pins 12 are driven to be movedfrom the open position to the holding position, and held at the holdingposition. In this manner, the substrate W is held by the stationary pins11 and the movable pins 12. In the upward movement of the splash guard 4to the treatment position, the guard permanent magnet 25 is moved towardthe protection disk permanent magnets 60 from the lower side, so thatdistances between the permanent magnet 25 and the permanent magnets 60are reduced. Thus, a repulsive magnetic force is correspondinglyincreased. The repulsive magnetic force levitates the protection disk 15from the upper surface of the turntable 7 toward the substrate W. Beforethe splash guard 4 reaches the treatment position, the protection disk15 reaches the adjacent position spaced the minute distance from thelower surface of the substrate W in close relation to the lower surfaceof the substrate W, whereby the flanges 20 provided at the lower ends ofthe guide shafts 17 respectively abut against the linear bearings 18.Thus, the protection disk 15 is held at the adjacent position.

In this state, the controller 40 opens the inert gas valve 73 to startsupplying the inert gas (Step S3). The supplied inert gas is spoutedfrom the upper end of the inert gas supply tube 70, and ejected radiallyabout the rotation axis 6 toward the narrow space defined between thelower surface of the substrate W and the protection disk 15 located atthe adjacent position by the action of the rectification member 86 andthe like. The inert gas is accelerated by an orifice defined between therestriction portion 90 provided on the peripheral edge of the protectiondisk 15 and the peripheral edge of the lower surface of the substrate Wto form a gas stream which is ejected at a higher flow speed laterallyof the substrate W.

The controller 40 further controls the rotation drive mechanism 3 tostart rotating the turntable 7, whereby the substrate W is rotated aboutthe rotation axis 6 (Step S4). The rotation speed may be, for example,about 100 rpm. In this state, the controller 40 opens the treatmentliquid valve 34. Thus, the treatment liquid is supplied from thetreatment liquid nozzle 31 toward the upper surface of the substrate W(Step S5). The supplied treatment liquid receives a centrifugal force onthe upper surface of the substrate W to spread outward over the entiresurface of the substrate W. The treatment liquid flowing outward fromthe substrate W by the centrifugal force is received by the splash guard4 to be drained. On the other hand, the controller 40 controls the armdrive mechanism 38 to cause the brush cleaning mechanism 35 to perform ascrub-cleaning process on the upper surface of the substrate W (StepS6). Thus, the upper surface of the substrate W is scrubbed with thecleaning brush 36 while the treatment liquid is supplied.

During the substrate treatment, the lower surface of the substrate W iscovered with the protection disk 15. In addition, the outward inert gasstream is formed in the space defined between the protection disk 15 andthe lower surface of the substrate W, so that the inert gas is ejectedoutward at a higher flow speed. Even if the treatment liquid mistscatters around the spin chuck 2, the mist is substantially preventedfrom adhering to the lower surface of the substrate W. This makes itpossible to selectively perform the scrub-cleaning process on the uppersurface of the substrate W, while preventing or suppressing the adhesionof the treatment liquid mist to the lower surface of the substrate Wwith the lower surface of the substrate W kept in a dry state withoutperforming a back rinsing process on the lower surface of the substrateW.

After the scrub-cleaning process, the controller 40 controls the armdrive mechanism 38 to retract the cleaning brush 36 from above the spinchuck 2 to the lateral side, and closes the treatment liquid valve 34 tostop spouting the treatment liquid from the treatment liquid nozzle 31(Step S7). Further, the controller 40 controls the rotative drivemechanism 3 to increase the rotation speed of the turntable 7. Thus, aspin-drying process is performed to spin out liquid droplets from theupper surface and the peripheral surface of the substrate W by acentrifugal force to dry the substrate W (Step S8). The rotation speedof the substrate W for the spin-drying process is, for example, 1500 to3000 rpm.

After the spin-drying process is performed for a predetermined period oftime, the controller 40 controls the rotative drive mechanism 3 to stoprotating the substrate W (Step S9). Further, the controller 40 closesthe inert gas valve 73 to stop supplying the inert gas (Step S10). Then,the controller 40 controls the guard drive mechanism 5 to move down thesplash guard 4 to the lower retracted position (Step S11). In thedownward movement of the splash guard 4, the distances between the guardpermanent magnet 25 and the protection disk permanent magnets 60 areincreased, so that the magnetic repulsive force generated between theguard permanent magnet 25 and the protection disk permanent magnets 60is reduced. Accordingly, the protection disk 15 is guided by the guidemechanism 19 to be moved down toward the upper surface of the turntable7 by its gravity. Thus, a space sufficient to receive the substrateholding hand 45 of the substrate transport robot is defined between theupper surface of the protection disk 15 and the lower surface of thesubstrate W. On the other hand, the guard permanent magnet 25 is notopposed to the pin driving permanent magnets 56, so that the externalforce for biasing the movable pins 12 to the holding position is lost.Instead, the cancelation permanent magnet 27 is opposed to the pindriving permanent magnets 56, whereby the movable pins 12 are biased tothe open position. Thus, the substrate W is released.

Subsequently, the controller 40 controls the substrate transport robotto insert the substrate holding hand 45 into the space defined betweenthe protection disk 15 and the lower surface of the substrate W. Then,the substrate holding hand 45 lifts the substrate W from the holdingpins 10 and, in this state, is retracted laterally of the spin chuck 2.Thus, the treated substrate W is unloaded (Step S12).

According to this embodiment, as described above, the guard permanentmagnet 25 retained in the splash guard 4 has an annular shape coaxialabout the rotation axis 6. Therefore, the guard permanent magnet 25 isconstantly opposed to the pin driving permanent magnets 56, andcontinuously applies a sufficient magnetic repulsive force to theprotection disk permanent magnets 60 during the rotation of theturntable 7. Thus, the external force for biasing the movable pins 12 tothe holding position and the external force for holding the protectiondisk 15 at the adjacent position close to the lower surface of thesubstrate W can be applied from the guard permanent magnet 25 providedin a non-rotation system in a non-contact state during the rotation ofthe turntable 7. In addition, the driving force is not provided byutilizing the rotation of the turntable 7. Therefore, even if thesubstrate W is rotated at a lower rotation speed in the scrub-cleaningprocessor the rotation of the substrate W is stopped, the movable pins12 provide a sufficient substrate holding force, and the protection disk15 is reliably kept at the adjacent position. This makes it possible totreat the upper surface of the substrate W while reliably preventing orsuppressing the adhesion of the treatment liquid mist to the lowersurface of the substrate W.

In this embodiment, the magnetic levitation mechanism 41 adapted tolevitate the protection disk 15 above the turntable 7 and the magneticdrive mechanism 42 adapted to drive the movable pins 12 share the guardpermanent magnet 25 retained in the splash guard 4. Thus, the guarddrive mechanism 5 for moving up and down the splash guard 4 can beshared as a drive source for the magnetic levitation mechanism 41 andthe magnetic drive mechanism 42, significantly simplifying theconstruction of the apparatus. Further, the magnetic levitationmechanism 41 and the magnetic drive mechanism 42 incorporate no drivingunit in a rotation system rotatable together with the turntable 7 and,therefore, each have a simplified structure. This further simplifies theconstruction of the substrate treatment apparatus 1. Further, themagnetic levitation mechanism 41 and the magnetic drive mechanism 42 areeach configured to transmit the driving force from the non-rotationsystem to the rotation system in a non-contact manner, eliminating thefrictional contact in a driving force transmission path during therotation of the turntable 7. This makes it possible to perform thesubstrate treatment process with higher cleanliness, while suppressingthe generation of particles.

In this embodiment, the inert gas is supplied into the space definedbetween the protection disk 15 located at the adjacent position and thelower surface of the substrate W, thereby more effectively preventing orsuppressing the adhesion of the treatment liquid mist to the lowersurface of the substrate W. Since the inert gas is ejected radially fromthe rotation axis 6 toward the outer peripheral edge of the substrate Wby the action of the rectification member 86 and the like, the inert gasstream flowing outward can be stably formed between the lower surface ofthe substrate W and the protection disk 15. This more effectivelyprevents or suppresses the adhesion of the treatment liquid mist to thelower surface of the substrate W. With the provision of the restrictionportion 90 on the outer peripheral edge of the protection disk 15, theinert gas stream flowing outward at a higher flow speed can be formed inthe vicinity of the outer peripheral edge of the substrate W. Thisfurther effectively prevents or suppresses the intrusion of thetreatment liquid mist into the space defined between the protection disk15 and the lower surface of the substrate W.

FIG. 7 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus 102 according to a second embodiment ofthe present invention. In FIG. 7, components corresponding to thoseshown in FIG. 1 are designated by the same reference characters as inFIG. 1. Although the guard drive mechanism 5 for moving up and down thesplash guard 4 is shared as the drive source for the magnetic levitationmechanism 41 and the magnetic drive mechanism 42 in the firstembodiment, a drive source dedicated for the magnetic levitationmechanism 41 is provided in the second embodiment.

In the second embodiment, more specifically, the magnetic levitationmechanism 41 includes protection disk permanent magnets 60, a disklifting permanent magnet 64 and a lift actuator 65. The disk liftingpermanent magnet 64 is an annular permanent magnet piece disposed in ahorizontal plane about the rotation axis 6, and has an annular magneticpole opposed to the protection disk permanent magnets 60 from a lowerside. The magnetic pole has the same polarity as lower magnetic poles ofthe protection disk permanent magnets 60. Therefore, the disk liftingpermanent magnet 64 generates an upward repulsive magnetic force withrespect to the protection disk permanent magnets 60. The disk liftingpermanent magnet 64 is incorporated and retained in an annular magnetretaining member 66. An actuation shaft 65 a of the lift actuator 65 isconnected to the magnet retaining member 66.

The lift actuator 65 is, for example, an air cylinder, which isconfigured to move up and down the actuator shaft 65 a parallel to therotation axis 6. The operation of the lift actuator 65 is controlled bythe controller 40. Thus, the lift actuator 65 can locate the disklifting permanent magnet 64 at an upper position and at a lowerposition. The lower position is set so that the disk lifting permanentmagnet 64 is located at a position sufficiently lower than the turntable7 and distances between the disk lifting permanent magnet 64 and theprotection disk permanent magnets 60 are sufficient to reduce a magneticrepulsive force between the disk lifting permanent magnet 64 and theprotection disk permanent magnets 60 to smaller than the gravity actingon the protection disk 15. The upper position is set higher than thelower position so that the protection disk 15 connected to the magnetretaining members 61 can be moved up to the adjacent position (treatmentheight position) close to the lower surface of the substrate W by amagnetic repulsive force generated between the disk lifting permanentmagnet 64 and the protection disk permanent magnets 60.

Therefore, when the lift actuator 65 is actuated to move up the disklifting permanent magnet 64 from the lower position to the upperposition, the magnetic repulsive force generated between the disklifting permanent magnet 64 and the protection disk permanent magnets 60surpasses the gravity acting on the protection disk 15 and other liftresistance (frictional force and the like) in the upward movement of thedisk lifting permanent magnet 64. Thus, the protection disk 15 islevitated from the upper surface of the turntable 7 to be moved up tothe adjacent position (treatment height position) close to the lowersurface of the substrate W. The flanges 20 provided at the lower ends ofthe guide shafts 17 are brought into abutment against the lower ends ofthe linear bearings 18 to limit the upward movement of the protectiondisk 15. On the other hand, when the lift actuator 65 is actuated tomove down the disk lifting permanent magnet 64 from the upper positionto the lower position, the gravity acting on the protection disk 15surpasses the magnetic repulsive force generated between the disklifting permanent magnet 64 and the protection disk permanent magnets 60and other downward movement resistance (frictional force and the like)in the downward movement of the disk lifting permanent magnet 64. Thus,the protection disk 15 is moved down from the adjacent position close tothe lower surface of the substrate W to reach the turntable 7.

In the second embodiment, the magnetic levitation mechanism 41 thusincludes the dedicated disk lifting permanent margent 64, and thededicated lift actuator 65 which moves up and down the disk liftingpermanent magnet 64. This makes it possible to move up and down theprotection disk 15 independently of the vertical movement of the splashguard 4 and the driving of the movable pins 12. Therefore, where thesplash guard 4 includes a plurality of treatment liquid ports which areprovided in vertically stacked relation to be selectively used accordingto the type of the treatment liquid, for example, the protection disk 15can be held at the adjacent position irrespective of the selective useof the treatment liquid ports.

FIG. 8 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus 103 according to a third embodiment ofthe present invention. In FIG. 8, components corresponding to thoseshown in FIG. 7 are designated by the same reference characters as inFIG. 7. In the third embodiment, a drive source dedicated for themagnetic levitation mechanism 41 is provided as in the secondembodiment.

In the third embodiment, the magnetic levitation mechanism 41 includesprotection disk permanent magnets 60, a disk lifting permanent magnet 64and a lift actuator 111. The disk lifting permanent magnet 64 is anannular permanent magnet piece disposed in a horizontal plane about therotation axis 6, and has an annular magnetic pole opposed to theprotection disk permanent magnets 60 from a lower side. The magneticpole has the same polarity as lower magnetic poles of the protectiondisk permanent magnets 60. Therefore, the disk lifting permanent magnet64 generates an upward repulsive magnetic force with respect to theprotection disk permanent magnets 60. The disk lifting permanent magnet64 is incorporated and retained in an annular magnet retaining member66. An actuation member 111 a of the lift actuator 111 is connected tothe magnet retaining member 66.

The lift actuator 111 includes a ball screw mechanism 112 and anelectric motor 113, and is configured to vertically move up and down theactuation member 111 a parallel to the rotation axis 6. The ball screwmechanism 112 includes a screw shaft 114 disposed vertically parallel tothe rotation axis 6, and a ball nut 115 threadingly engaged with thescrew shaft 114. The actuation member 111 a is connected to the ball nut115. The screw shaft 114 has an upper end supported by a bearing 116,and a lower end connected to a drive shaft 113 a of the electric motor113 via a coupling 117. The electric motor 113 is provided with arotational position detecting unit 118 which detects the rotationalposition of the drive shaft 113 a. The rotational position detectingunit 118 includes, for example, a rotary encoder, and an output signalof the rotary encoder is inputted to the controller 40.

The operation of the lift actuator 111, more specifically, the operationof the electric motor 113, is controlled by the controller 40. Thus, thelift actuator 111 can locate the disk lifting permanent magnet 64 at anyheight position between an upper position and a lower position. Thelower position is set so that the disk lifting permanent magnet 64 islocated at a position sufficiently lower than the turntable 7 anddistances between the disk lifting permanent magnet 64 and theprotection disk permanent magnets 60 are sufficient to reduce a magneticrepulsive force generated between the disk lifting permanent magnet 64and the protection disk permanent magnets 60 to smaller than the gravityacting on the protection disk 15. The upper position is set higher thanthe lower position so that the protection disk 15 connected to themagnet retaining members 61 can be moved up to the adjacent position(treatment height position) close to the lower surface of the substrateW by a magnetic repulsive force generated between the disk liftingpermanent magnet 64 and the protection disk permanent magnets 60.

Therefore, when the lift actuator 111 is actuated to move up the disklifting permanent magnet 64 from the lower position to the upperposition, the magnetic repulsive force generated between the disklifting permanent magnet 64 and the protection disk permanent magnets 60surpasses the gravity acting on the protection disk 15 and other liftresistance (frictional force and the like) in the upward movement of thedisk lifting permanent magnet 64. Thus, the protection disk 15 islevitated from the upper surface of the turntable 7 to be moved up tothe adjacent position (treatment height position) close to the lowersurface of the substrate W. The flanges 20 provided at the lower ends ofthe guide shafts 17 are respectively brought into abutment against thelower ends of the linear bearings 18 to limit the upward movement of theprotection disk 15. On the other hand, when the lift actuator 111 isactuated to move down the disk lifting permanent magnet 64 from theupper position to the lower position, the gravity acting on theprotection disk 15 surpasses the magnetic repulsive force generatedbetween the disk lifting permanent magnet 64 and the protection diskpermanent magnets 60 and other downward movement resistance (frictionalforce and the like) in the downward movement of the disk liftingpermanent magnet 64. Thus, the protection disk 15 is moved down from theadjacent position close to the lower surface of the substrate W to reachthe turntable 7.

The lift actuator 111 includes the ball screw mechanism 112 and thelike, so that the position of the disk lifting permanent magnet 64 canbe controlled at any position intermediate between the upper positionand the lower position as described above. More specifically, thecontroller 40 detects the rotational position of the drive shaft 113 aof the electric motor 113 with reference to the output signal of therotational position detecting unit 118, and detects the height positionof the disk lifting permanent magnet 64 indirectly based on therotational position. Thus, the controller 40 can control the heightposition of the disk lifting permanent magnet 64 at any height positionbetween the upper position and the lower position. Thus, the position ofthe protection disk 15 can be controlled not only at the two positions,i.e., the upper position and the lower position, but also at any heightposition between the turntable 7 and the substrate holding heightposition above the spin chuck 2.

The controller 40 may be programmed so as to change the height positionof the protection disk 15 according to a substrate treatment to beperformed. Where the upper surface of the substrate W is scrubbed withthe cleaning brush 36, for example, the substrate W is liable to bewarped downward. To cope with this, the controller 40 levitates theprotection disk 15 from the turntable 7 to locate the protection disk 15at a scrub-cleaning height position so as to prevent the substrate Wfrom contacting the protection disk 15 even if the substrate W is warpeddownward. That is, the controller 40 controls the lift actuator 111 soas to locate the protection disk 15 at the scrub-cleaning heightposition. On the other hand, where a liquid treatment process isperformed on the substrate W simply by supplying a chemical liquid or arinse liquid to the substrate W without the scrubbing or where aspin-drying process is performed on the substrate W by rotating thesubstrate W to spin out a liquid component from the substrate W, thesubstrate W is not significantly warped downward. Therefore, thecontroller 40 controls the lift actuator 111 to locate the protectiondisk 15 at a position higher than the scrub-cleaning height position toreduce the distance between the protection disk 15 and the lower surfaceof the substrate W. This more reliably prevents the intrusion of thetreatment liquid mist into the space below the lower surface of thesubstrate W.

In the third embodiment, the magnetic levitation mechanism 41 thusincludes the dedicated disk lifting permanent margent 64, and thededicated lift actuator 111 which moves up and down the disk liftingpermanent magnet 64. This makes it possible to move up and down theprotection disk 15 independently of the vertical movement of the splashguard 4 and the driving of the movable pins 12. In addition, the liftactuator 111 is configured so as to control the position of theprotection disk 15 at any height position between the turntable 7 andthe substrate holding height position. Thus, the distance between theprotection disk 15 and the lower surface of the substrate W can beproperly adjusted according to a treatment process to be performed.

FIG. 9 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus 104 according to a fourth embodiment ofthe present invention. In FIG. 9, components corresponding to thoseshown in FIG. 8 are designated by the same reference characters as inFIG. 8.

In this embodiment, a second disk lifting permanent magnet 67 opposed tothe protection disk permanent magnets 60 from an upper side is providedin addition to the disk lifting permanent magnet 64 (hereinafterreferred to as “first disk lifting permanent magnet 64”). That is, theprotection disk permanent magnets 60 are sandwiched between the firstand second disk lifting permanent magnets 64 and 67 from the upper andlower sides. The second disk lifting permanent magnet 67 is an annularpermanent magnet piece disposed in a horizontal plane about the rotationaxis 6, and has an annular magnetic pole opposed to the protection diskpermanent magnets 60 from the upper side. The magnetic pole has the samepolarity as the upper magnetic poles of the protection disk permanentmagnets 60. Therefore, the second disk lifting permanent magnet 67applies a downward repulsive magnetic force to the protection diskpermanent magnets 60. Therefore, the protection disk permanent magnets60 receive an upward repulsive magnetic force from the first disklifting permanent magnet 64 from the lower side, and receive thedownward repulsive magnetic force from the second disk lifting permanentmagnet 67 from the upper side. Then, the protection disk permanentmagnets 60 are held between the first and second disk lifting permanentmagnets 64 and 67 in a non-contact manner at a position at which theserepulsive magnetic forces are balanced with the gravity and the likeacting on the protection disk 15.

The first and second disk lifting permanent magnets 64, 67 areincorporated and retained in an annular magnet retaining member 68. Anactuation member 111 a of the lift actuator 111 is connected to themagnet retaining member 68. The magnetic retaining member 68 has alaterally open U-shaped cross section (outwardly open U-shaped crosssection) taken perpendicularly to its circumference, and includes anannular lower retaining portion 68 a which retains the first disklifting permanent magnet 64, an annular upper retaining portion 68 bwhich retains the second disk lifting permanent magnet 67, and a tubularconnection portion 68 c connecting inner peripheral edge portions of thelower retaining portion 68 a and the upper retaining portion 68 b. Aspace for accommodating the protection disk permanent magnets 60 isprovided between the lower retaining portion 68 a and the upperretaining portion 68 b outward of the tubular connection portion 68 c.Distal end portions 61 a of the magnet retaining members 61 are insertedin this space from a radially outward side about the rotation axis.

In this embodiment, the magnet retaining members 61 each include apendent portion 61 b extending downward from the protection disk 15, andthe distal end portions 61 a each extend inward from a lower end of thependent portion 61 b toward the rotation axis 6. Thus, the magnetretaining members 61 each have a generally L-shape. The protection diskpermanent magnets 60 are each embedded in the distal end portion 61 a.

The first and second disk lifting permanent magnets 64, 67 each haveannular magnetic poles. With the spin chuck 2 assuming any rotationalposition, therefore, the protection disk permanent magnets 60 receivethe magnetic forces from the first and second disk lifting permanentmagnets 64, 67 to be thereby held between the first and second disklifting permanent magnets 64 and 67 in a non-contact state.

This arrangement provides the same effects as the arrangement accordingto the third embodiment. In addition, the protection disk permanentmagnets 60 receive the magnetic repulsive forces from the upper andlower sides, making it possible to accurately control the verticalpositions of the protection disk permanent magnets 60. This improves theposition controlling accuracy for controlling the position of theprotection disk 15, thereby further suppressing the adhesion of thetreatment liquid mist to the lower surface of the substrate W.

FIG. 10 is a schematic sectional view for explaining the construction ofa substrate treatment apparatus 105 according to a fifth embodiment ofthe present invention. In FIG. 10, components corresponding to thoseshown in FIG. 7 are designated by the same reference characters as inFIG. 7. In the fifth embodiment, a drive source dedicated for themagnetic levitation mechanism 41 is provided as in the secondembodiment.

In the fifth embodiment, the magnetic levitation mechanism 41 includesprotection disk permanent magnets 60, a disk lifting electromagneticdevice 97 and a height controlling electromagnetic device 98.

The disk lifting electromagnetic device 97 has an annular magnetic pole97 a disposed in a horizontal plane about the rotation axis 6, and theannular magnetic pole 97 a is opposed to the protection disk permanentmagnets 60 from the lower side. When the disk lifting electromagneticdevice 97 is energized with a first direction electric current flowingin a first direction to be thereby magnetized, the magnetic pole 97 ahas the same polarity as the lower magnetic poles of the protection diskpermanent magnets 60. Further, when the disk lifting electromagneticdevice 97 is energized with a second direction electric current flowingin a second direction opposite from the first direction to be therebymagnetized, the magnetic pole 97 a has a polarity different from thepolarity of the lower magnetic poles of the protection disk permanentmagnets 60. Therefore, when the disk lifting electromagnetic device 97is energized with the first direction electric current, an upwardrepulsive magnetic force acts on the protection disk permanent magnets60. When the disk lifting electromagnetic device 97 is energized withthe second direction electric current, a downward attractive magneticforce acts on the protection disk permanent magnets 60. When theenergization is stopped, these magnetic forces disappear.

With the disk lifting electromagnetic device 97 energized with thesecond direction electric current or with the disk liftingelectromagnetic device 97 not energized, the protection disk 15 iscontrolled to be located at the lower position close to the turntable 7.With the disk lifting electromagnetic device 97 energized with the firstdirection electric current, on the other hand, the protection disk 15 islevitated above the turntable 7 by a repulsive magnetic force generatedbetween the magnetic pole 97 a and the protection disk permanent magnets60. The energization of the disk lifting electromagnetic device 97 iscontrolled by the controller 40.

The height controlling electromagnetic device 98 includes a plurality ofelectromagnetic units U1, U2, U3, . . . respectively having annularmagnetic poles m1, m2, m3, . . . each disposed in a horizontal planeabout the rotation axis 6. The magnetic poles m1, m2, m3, . . . areequidistantly arranged vertically parallel to the rotation axis 6 so asto respectively have cylindrical magnetic pole surfaces having the sameradius and facing outward (away from the rotation axis 6). Morespecifically, the magnetic poles m1, m2, m3, . . . are arranged alongthe range of the vertical movement and the rotational movement of theprotection disk permanent magnets 60 so as to exert magnetic forces onthe protection disk permanent magnets 60 without interference with themagnet retaining members 61. In the arrangement shown in FIG. 10, themagnetic poles m1, m2, m3, . . . are disposed inward of the movementrange of the protection disk permanent magnets 60, but may be disposedoutward of the movement range of the protection disk permanent magnets60. Further, the magnetic poles m1, m2, m3, . . . may be disposed inwardand outward of the movement range of the protection disk permanentmagnets 60.

The electromagnetic units U1, U2, U3, . . . are each configured so thatthe magnetic poles m1, m2, m3, . . . thereof each have one of oppositepolarities when they are energized with an electric current flowing inone of opposite directions, and each have the other polarity when theyare energized with an electric current flowing in the other direction.Therefore, an attractive magnetic force (attractive force) or arepulsive magnetic force (repulsive force) is generated between themagnetic poles m1, m2, m3, . . . and the protection disk permanentmagnets 60 according to the direction of the electric current to beapplied to the electromagnetic units U1, U2, U3, . . . and the heightposition of the protection disk permanent magnets 60. The magnitude ofthe magnetic force depends on the magnitude of the electric current tobe applied to the electromagnetic units U1, U2, U3, . . . .

Thus, the height position of the protection disk permanent magnets 60can be controlled by controlling the direction and the magnitude of theelectric current to be applied to the electromagnetic units U1, U2, U3,. . . . That is, the controller 40 controls the energization of theelectromagnetic units U1, U2, U3, . . . to control the height positionof the protection disk permanent magnets 60, i.e., the height positionof the protection disk 15.

The controller 40 levitates the protection disk 15 from the turntable 7and, when controlling the height position of the protection disk 15,energizes the disk lifting electromagnetic device 97 with the firstdirection electric current and controls the energization of theelectromagnetic units U1, U2, U3, . . . according to a control targetheight position. Thus, the protection disk 15 can be located at thecontrol target height position between the turntable 7 and the substrateholding height position. Therefore, the protection disk 15 can belocated at a proper height position according to the treatment processas in the third embodiment.

The magnitude of the magnetic repulsive force generated between themagnetic pole 97 a and the protection disk permanent magnet 60 can becontrolled by controlling the magnitude of the electric current to beapplied to the disk lifting electromagnetic device 97. This makes itpossible to control the height position of the protection disk permanentmagnets 60, i.e., the height position of the protection disk 15.Therefore, the height position of the protection disk 15 may becontrolled by controlling the energization of the disk liftingelectromagnetic device 97 without the provision of the heightcontrolling electromagnetic device 98.

FIG. 11 is a diagram showing an exemplary arrangement for detecting theposition of the protection disk 15. In this exemplary arrangement, aphotosensor 121 is provided for checking if the protection disk 15 islocated at the lower position on the turntable 7. An output signal ofthe photosensor 121 is inputted to the controller 40. The photosensor121 is disposed on a lateral side of the turntable 7, and has adetection light axis 121 a which is adjusted to extend in a horizontalplane at the lower position of the protection disk 15. When theprotection disk 15 is located at the lower position, the detection lightaxis 121 a of the photosensor 121 aligns with the protection disk 15.Therefore, the presence of the protection disk 15 at the lower positioncan be detected by detecting the blocking or the reflection of light bythe protection disk 15. The controller 40 checks the operation of themagnetic levitation mechanism 41 by thus checking the presence of theprotection disk 15 at the lower position.

FIG. 12 is a diagram showing another exemplary arrangement for detectingthe position of the protection disk 15. In this exemplary arrangement, aline sensor 122 is provided for detecting the height position of theprotection disk 15 above the turntable 7. An output signal of the linesensor 122 is inputted to the controller 40. The line sensor 122 is of amultiple-light-axis type which includes a plurality of light axes a1,a2, a3, . . . located at different height positions. That is, the lightexes a1, a2, a3, . . . are parallel to each other, and each extend in ahorizontal plane. The light axes a1, a2, a3, . . . are disposed betweenthe upper surface of the turntable 7 and the substrate holding heightposition as corresponding to different height positions of theprotection disk 15. Therefore, one of the light axes a1, a2, a3, . . .aligns with the protection disk 15 depending on the height position ofthe protection disk 15. Thus, the height position of the protection disk15 can be detected by detecting the blocking or the reflection of lighttraveling along a corresponding one of the light axes by the protectiondisk 15. The controller 40 checks the operation of the magneticlevitation mechanism 41 or controls the magnetic levitation mechanism 41by thus acquiring information about the height position of theprotection disk 15.

FIG. 13 is a diagram showing further another exemplary arrangement fordetecting the position of the protection disk 15. In this exemplaryarrangement, a camera 123 is provided for detecting the height positionof the protection disk 15 above the turntable 7. An image signaloutputted from the camera 123 is inputted to the controller 40. Thecamera 123 is disposed so as to take an image of an imaging regionbetween the turntable 7 and the substrate holding height position from alateral side of the spin chuck 2. Therefore, the protection disk 15 ispresent in the imaging region. The controller 40 computes the heightposition of the protection disk 15 by processing the image signaloutputted from the camera 123. The controller 40 checks the operation ofthe magnetic levitation mechanism 41 or controls the magnetic levitationmechanism 41 by thus acquiring information about the height position ofthe protection disk 15.

FIG. 14 is a diagram showing still another exemplary arrangement fordetecting the position of the protection disk 15. In this exemplaryarrangement, a distance sensor 124 is provided for detecting the heightposition of the protection disk 15 above the turntable 7. An outputsignal of the distance sensor 124 is inputted to the controller 40. Inthe exemplary arrangement shown in FIG. 14, the distance sensor 124 isdisposed below a magnet retaining member 61, and is configured to detecta distance to the magnet retaining member 61. Since the magnet retainingmember 61 is connected to the protection disk 15, the distance detectedby the distance sensor 124 corresponds to the height of the protectiondisk 15 above the turntable 7. The distance sensor 124 may be adapted tomeasure the distance by generating a probe signal such as an ultrasonicprobe signal or an optical probe signal and detecting a probe signalreflected on the magnet retaining member 61. The controller 40 acquiresinformation about the height position of the protection disk 15 based onthe output signal of the distance sensor 124, and checks the operationof the magnetic levitation mechanism 41 or controls the magneticlevitation mechanism 41 based on the acquired information.

While the embodiments of the present invention have thus been described,the invention may be embodied in other ways. As shown by atwo-dot-and-dash line in FIG. 4, a skirt portion 93 serving as a lateralside covering member for covering the space defined between the lowersurface of the substrate W and the turntable 7 from a lateral side maybe fixed to a peripheral edge portion of the protection disk 15. Theskirt portion 93 has an annular shape extending along the peripheraledge of the protection disk 15, and has a generally laterally-invertedL-shaped section taken perpendicularly to the peripheral edge. Morespecifically, the skirt portion 93 includes a horizontal portion 94horizontally extending along a lower surface of the protection disk 15,and a pendent portion 95 extending vertically downward from thehorizontal portion 94 outside the turntable 7. When the protection disk15 is located at the adjacent position, the skirt portion 93 covers thespace defined between the lower surface of the protection disk 15 andthe turntable 7 from the lateral side, thereby substantially preventingan ambient atmosphere from being caught into the space. This stabilizesan air stream occurring around the spin chuck 2, making it possible toperform a higher-quality substrate treatment. When the protection disk15 is located at the lower position, the skirt portion 93 is retracteddownward together with the protection disk 15, and the space definedbetween the upper surface of the protection disk 15 and the substrateholding height position of the holding pins 10 is laterally open.Therefore, the substrate W can be loaded and unloaded by inserting thesubstrate holding hand 45 into the space.

Although the guard drive mechanism 5 for moving up and down the splashguard 4 doubles as a drive source for the magnetic drive mechanism 42 inthe embodiments described above, the drive source for the magnetic drivemechanism 42 may be additionally provided.

In the embodiments described above, the magnetic drive mechanism 42 isprovided for driving the movable pins 12 by the magnetic force, but adrive mechanism for driving the movable pins 12 may be incorporated inthe turntable 7. Although the inert gas is supplied into the spacedefined between the protection disk 15 and the lower surface of thesubstrate W in the embodiments described above, the supply of the inertgas may be obviated.

Although, in the embodiments described above, the inert gas supply isstopped after the substrate rotation is stopped, the inert gas supplymay be stopped when the spin dry process is initiated.

Although the embodiments described above are directed to an exemplarycase in which the upper surface of the substrate W is scrubbed with thecleaning brush, the present invention is applicable to a case in whichthe upper surface of the substrate W is cleaned by supplying a liquiddroplet jet stream onto the surface of the substrate W from a bifluidnozzle rather than by using the cleaning brush. Additionally, thepresent invention is applicable to an ultrasonic cleaning process to beperformed to clean the substrate by supplying a treatment liquidvibrated by ultrasonic waves onto the surface of the substrate, and ahigh pressure jet cleaning process to be performed to clean thesubstrate by supplying a pressurized treatment liquid at a higher flowrate onto the surface of the substrate. The present invention isapplicable not only to these cleaning processes but also to a coatingprocess in which the surface of the substrate is coated with a resist,and a developing process in which a developing liquid is supplied to aresist film after exposure of the resist film.

Further, the embodiments described above are directed to an arrangementfor driving the movable pins 12 by utilizing the attractive forcegenerated between the permanent magnets, but the driving of the movablepins 12 may be achieved by providing non-magnetized magnetic memberseccentrically to the rotation axes 12 a of the movable pins 12 insteadof the pin driving permanent magnets 56. Further, the driving of themovable pins 12 may be achieved by providing permanent magnetseccentrically to the rotation axes 12 a of the movable pins 12 andproviding non-magnetized magnetic members at positions corresponding tothe guard permanent magnet 25 and the cancelation permanent magnet 27.

In the embodiments described above, the magnetic pole direction of theguard permanent magnet 25 is horizontal by way of example. The magneticpole direction of the guard permanent magnet 25 may be vertical, or maybe inclined with respect to a horizontal plane.

The embodiments described above are directed to a case in which theturntable 7 of the spin chuck 2 is located at the predetermined heightposition and the splash guard 4 is movable up and down relative to theturntable 7 along the rotation axis 6. However, the relative movement ofthe splash guard 4 and the turntable 7 may be achieved by fixing thesplash guard 4 and moving up and down the spin chuck 2 or by moving upand down both the spin chuck 2 and the splash guard 4.

While the present invention has been described in detail by way of theembodiments thereof, it should be understood that these embodiments aremerely illustrative of the technical principles of the present inventionbut not limitative of the invention. The spirit and scope of the presentinvention are to be limited only by the appended claims.

This application corresponds to Japanese Patent Application Nos.2011-277402 and 2012-74620 filed in the Japan Patent Office on Dec. 19,2011 and Mar. 28, 2012, respectively, the disclosure of which isincorporated herein by reference by its entirety.

What is claimed is:
 1. A substrate treatment apparatus comprising: asubstrate holding and rotating device; and a treatment liquid supplyunit which supplies a treatment liquid to an upper surface of asubstrate held by the substrate holding and rotating device; thesubstrate holding and rotating device comprising: a turntable rotatableabout a vertical rotation axis; a rotative drive unit which rotates theturntable; a holding member which is provided on the turntable andhorizontally holds the substrate in upwardly spaced relation to theturntable; a protection disk disposed between the turntable and asubstrate holding position at which the substrate is held by the holdingmember, and attached to the turntable so as to be vertically movablerelative to the turntable between a lower position and an adjacentposition closer than the lower position to a lower surface of thesubstrate held by the holding member above the lower position, theprotection disk having a notch provided in a peripheral portion thereofat a position corresponding to a position of the holding member toborder the holding member; a lateral side covering member which isattached to the protection disk and covers a space defined between thesubstrate held by the holding member and the turntable from a lateralside of the turntable; wherein the lateral side covering member includesa skirt portion having a first portion extending radially outwardly froma peripheral edge of the protection disk and a second portion extendingdownwardly from the first portion outside of the turntable; a magneticlevitation mechanism including a first magnet attached to the protectiondisk, a second magnet which has an annular shape coaxial about thevertical rotation axis and generates a repulsive force with respect tothe first magnet, a first support member which non-rotatably supportsthe second magnet, and a first relative movement mechanism which movesthe first support member relative to the turntable so as to change adistance between the first magnet and the second magnet, the magneticlevitation mechanism being configured to levitate the protection diskfrom the turntable by the repulsive force generated between the firstmagnet and the second magnet; and an inert gas supply unit whichsupplies an inert gas, which does not undergo chemical reactions underoperating conditions of the substrate treatment apparatus, to a spacedefined between the substrate held and rotated by the substrate holdingand rotating device and the protection disk located at the adjacentposition; wherein the protection disk has a restriction portion providedon an upper surface thereof, the restriction portion defines an orificebetween the restriction portion and a peripheral edge of the lowersurface of the substrate held by the holding member, and the orificerestricts an inert gas flow passage defined between the substrate heldby the holding member and the protection disk.
 2. The substratetreatment apparatus according to claim 1, further comprising a receivingmember which receives a treatment liquid supplied from the treatmentliquid supply unit to the substrate held by the substrate holding androtating device and flowing outward from the surface of the substrate,wherein the first support member is fixed to the receiving member,wherein the first relative movement mechanism is configured to move thereceiving member and the turntable relative to each other.
 3. Thesubstrate treatment apparatus according to claim 1, wherein the inertgas supply unit includes an inert gas nozzle which ejects the inert gasradially toward a peripheral edge of the substrate held by the holdingmember from a rotation center of the turntable.